/*
 * Copyright (c) 2007, 2015, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */
/*
 * Copyright 2001-2004 The Apache Software Foundation.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.sun.org.apache.xerces.internal.impl.xs.models;

import com.sun.org.apache.xerces.internal.xni.QName;
import com.sun.org.apache.xerces.internal.impl.xs.SubstitutionGroupHandler;
import com.sun.org.apache.xerces.internal.impl.xs.XMLSchemaException;

import java.util.Vector;
import java.util.ArrayList;

/**
 * XSEmptyCM is a derivative of the abstract content model base class that
 * handles a content model with no chilren (elements).
 *
 * This model validated on the way in.
 *
 * @author Elena Litani, Lisa Martin
 * @author IBM
 * @version $Id: XSEmptyCM.java,v 1.7 2009/07/28 15:18:11 spericas Exp $
 * @xerces.internal
 */
public class XSEmptyCM implements XSCMValidator {

  //
  // Constants
  //

  // start the content model: did not see any children
  private static final short STATE_START = 0;

  private static final Vector EMPTY = new Vector(0);

  //
  // Data
  //

  //
  // XSCMValidator methods
  //

  /**
   * This methods to be called on entering a first element whose type
   * has this content model. It will return the initial state of the content model
   *
   * @return Start state of the content model
   */
  public int[] startContentModel() {
    return (new int[]{STATE_START});
  }


  /**
   * The method corresponds to one transaction in the content model.
   *
   * @param elementName the qualified name of the element
   * @param currentState Current state
   * @param subGroupHandler the substitution group handler
   * @return element index corresponding to the element from the Schema grammar
   */
  public Object oneTransition(QName elementName, int[] currentState,
      SubstitutionGroupHandler subGroupHandler) {

    // error state
    if (currentState[0] < 0) {
      currentState[0] = XSCMValidator.SUBSEQUENT_ERROR;
      return null;
    }

    currentState[0] = XSCMValidator.FIRST_ERROR;
    return null;
  }


  /**
   * The method indicates the end of list of children
   *
   * @param currentState Current state of the content model
   * @return true if the last state was a valid final state
   */
  public boolean endContentModel(int[] currentState) {
    boolean isFinal = false;
    int state = currentState[0];

    // restore content model state:

    // error
    if (state < 0) {
      return false;
    }

    return true;
  }

  /**
   * check whether this content violates UPA constraint.
   *
   * @param subGroupHandler the substitution group handler
   * @return true if this content model contains other or list wildcard
   */
  public boolean checkUniqueParticleAttribution(SubstitutionGroupHandler subGroupHandler)
      throws XMLSchemaException {
    return false;
  }

  /**
   * Check which elements are valid to appear at this point. This method also
   * works if the state is in error, in which case it returns what should
   * have been seen.
   *
   * @param state the current state
   * @return a Vector whose entries are instances of either XSWildcardDecl or XSElementDecl.
   */
  public Vector whatCanGoHere(int[] state) {
    return EMPTY;
  }

  public ArrayList checkMinMaxBounds() {
    return null;
  }

} // class XSEmptyCM
